1stly, are you overstimulating your ms through pumping? If yes, then I'll suggest you slowly cut down and pump only to relieve engorgement. dont't drain the breast fully through pumping cos you want to manage your supply, not over stimulate it again.
Do you observe anything different about your baby's poo? If your problem lies in too much foremilk intake, then baby's poo is usually foamy and bright green. If not, then you might want to re-examine your food intake. There are other foods that might result in gassiness other than milk. Milk products like cheese, yoghurt, etc can also induce gassiness. Cruciferous veg like broccoli, cabbage are also known to cause gas.
If you suspect your problems lies in your eating certain foods, then try eliminating the food for a week. If baby's fine, then you might want to intro the food into your own diet again after 1 wk and see if there's a reaction again.